Actuating apparatus for a diverter for sheet articles

ABSTRACT

In an actuating apparatus for a diverter for sheet articles fed at equal time intervals along a first path, the diverter being disposed at a fork junction where selected articles are to be diverted out of the first path into a second path, actuating linkage is provided for causing the diverter to effect diversion of the articles to the said second path in response to a signal. Control means disposed upstream of the fork junction are effective to deliver the signal when there is some irregularity appertaining to one of the articles or after a predetermined number of articles has passed. An energy store biases the actuating linkage towards a position in which diversion is effected but locking means hold the acutating linkage against the bias of the energy store. The locking means are at least indirectly coupled to a shaft that is rotated so that the locking means become ineffective at least once during each time interval. The locking means comprise a double-acting abutment insertable into the oscillatory path of a lever which is connected to the diverter, is movable therewith when the diverter is actuated and is provided with appropriate counter-abutment surfaces. Means are provided for charging the energy store during a fraction of one time interval in response to the signal and for keeping it charged during a predetermined period, a second energy store being provided which seeks to return the diverter after it has been actuated.

United States Patent i191 Feldkamper 1 Feb. 18, 1975 41 ACTUATING APPARATUS FOR A DIVERTER FOR SHEET ARTICLES [75] Inventor: Richard Feldk'zimpen Lengerich,

Germany [73] Assignee: Windmoller & Holscher, Lengerich,

Germany [22] Filed: June 12, 1973 [21] Appl. No.: 369,198

[30] Foreign Application Priority Data June 15, 1972 Germany 2229286 [52] US. Cl. 271/64 [51] Int. Cl B65h 29/60 [58] Field of Search 211/64 [56] References Cited I UNITED STATES PATENTS 1,071,272 8/1913 Spiess 271/64 3,556,518 1/1971 Brockmuller et al. 271/64 3,684,279 8/1972 Heimlicher 271/64 Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney, Agent, or FirmFleit & Jacobson [57] ABSTRACT In an actuating apparatus for a diverter for sheet artidiverter being disposed at a fork junction where se lected articles are to be diverted out of the first path into a second path, actuating linkage is provided for causing the diverter to effect diversion of the articles to the said second path in response to a signal. Control means disposed upstream of the fork junction are effective to deliver the signal when there is some irregularity appertaining to one of the articles or after a predetermined number of articles has passed. An energy store biases the actuating linkage towards a position in which diversion is effected but locking meanshold the acutating linkage against the bias of the energy store. The locking means are at least-indirectly coupled to a shaft that is rotated so that the locking means become ineffective at least once during each time interval. The locking means comprise a double-acting abutment insertable into the oscillatory path of a lever which is connected to the diverter, is movable therewith when the diverter is actuated and is provided with appropriate counter-abutment surfaces. Means are provided 5 C1aims,'2 Drawing Figures ACTUATING APPARATUS FOR A DIVERTER FOR SHEET ARTICLES The invention relates to an actuating apparatus for a diverter for sheet articles movingat equal time intervals along a first path, the diverter being disposed at a fork junction where selected articles are to be diverted out of the first path into a second path, the actuating apparatus comprising actuating linkage for causing the diverter to effect .diversion of the articles to the said second path in response to a signal, control means upstream of the fork junction for delivering said-signal when there is some irregularity appertaining to an article or after a predetermined number of articles has passed, an energy store for biassing the actuatinglinkage towards a position in which diversion is effected, and locking means for holding the actuating linkage against the bias of the energy store. I

In paper processing machines or the like, sheet articles moving at a very small spacing from one another are processed at rapid timeintervals, In order to sort out defective articles or to divert the articles into a different path after a predetermined number of the articles has passed along a first path, the time that is available for the diversion is the interval between two successive sheet articles. If the diverter is actuated too soon, i.e., before'the trailing edgeof the article preceding the defective article has passed the diverter, disruption is likely to occur, especially at high operating speeds-If one considers that the space between successive articles may amount to only five to ten percent of the pitch at which the articles are fed and that one aims to feed the articles at rates of 400 and more per minute, it will be recognized that the time at which the actuator has to be operated must be very exactly determined and the actual actuating period must be less than about milliseconds. An actuating apparatus of the kind hereinbefore referred to is described in GermanSpecification No. 1,278,212. It comprises an actuatingpin for an unlocking mechanism.- The actuating pin is oscillatory in sequence with the time interval between successive sheet articles and it is lifted by an electromagnet. In its normal position, the pin oscillates freely beneath an actuating abutment. When raised, it engages the unlocking mechanism and actuates the latter. The actuating linkage for the diverter is then moved under the influence of the prebias'provided by the energy store. This equipment is quite costly because it involves many mechanical parts. In addition, it can only be' used for diverting articles some considerable time after the diverter waspreviously actuated. It is not suitable for sorting out defective sheet articles which might occur in very rapid sequence, e.g., happens to be defective.

A similar actuating apparatus is also known from German Specification No. 1,044,589 which is suitable for sorting out defective sheet articles. In that case, the actuating linkage is provided with an energy a store, namely a spring, which seeks to displace the linkage in the sense of diverting the articles. Actual actuation, however, takes place with the aid of a cam disqwhich comprises a cam t'roughand which rotates in sequence with the time interval between the moving, sheet articles. A cam follower roller which is carried by anactuating arm and is pressed against the cam disc by a spring passes over the camtrough at the instant when the gap between successive articles coincides with the if every alternate article diverter. Normally, i.e., whenthere is no defective article, the actuating linkage is locked by an electromagnetically actuatable locking mechanism and the cam follower roller cannot pass through the cam trough but must override it in the lifted condition as a result of locking. When a defective article is indicated by the control means, unlocking takes placein good time and the camfollower roller can now sweep along the cam trough and the spring may actuate the diverter in accordance with thetroughl The disadvantage of this actuator is that the diverter remains in the actuated condition for only a short time, namely only once the cam follower roller is passing through the trough of the cam. Even whilst the defective workpiece is still passing through the equipment the diverter returns to its original position. This means that a fairly long portion of the defective workpiece will pass through when the diverter is already back in its normal position and consequently the equipment is not suitable for high production speeds because disruptions would occur'. In addition, the construction of this known equipment is such that the actuator executes a complete .a'ctuatingcycle for each defective sheet article, even if several defective articles happen to follow one another (which is often the case when machines are restarted after standstill). The rapid and frequentactuation of the diverter would cause excessive wear of the components. Yet another disadvantage is that the actuator is not suitable for the prolonged deviation of sheet articles because actuation of the diverter in one direction takes place at a different instant of one time interval than actuation in the other direction. Actuation in one direction is effected by one side of the cam and actuation in the other direction by' the other side,

this necessarily giving rise to time differences.

The invention aims to provide an actuating apparatus which, in principle, is suitable for sorting out individual defective sheet articles or for feeding the sheet articles in alternately opposite directions after a predetermined number of the articles has passed in each direction. Use of the actuatingapparatus to sort out defective articles makes it necessary for the diverter to be returned to its original position only after the defective article has been diverted. If several defective articles follow one another in succession, the diverter should remain in the diverting position. If the apparatus is to be used for its other purpose, it should be possible toswitch the di-. I

verterfor delivery of the articles in one direction or the other always at the same instant of each time interval. According to the invention, an actuating apparatus for a diverter for sheet articles moving at equal time intervals along a first path,- the diverter being disposed at a fork junction where selected articles are to be diverted out of the first path into a'second path, comprises actuatinglinkage for causing the diverter to effect diversion of the articles to the said second path in ,response to a signal, control means upstream'of said fork junction for delivering said signal when there is some irregularity appertaining 'toan article or after a predetermined number of articles has passed, an energystore for biassing the actuating linkage towards a position in which diversion is effected, and locking means for holding the actuating linkage against the bias of the energy store, wherein the locking means are at least indirectly coupled to a shaft, which is rotatable in sequence with said equaltime intervals", so that they are released at least once during each time interval,

v wherein the locking means comprise a double-acting abutment insertable into the oscillatory path of a lever which is connected to the diverter, is movable therewith when the diverter is actuated and is provided with appropriate counter-abutment surfaces, the abutment being dimensioned so as to be adapted to lock the diverter in either of two limiting positions, wherein the energy store is rapidly chargeable, wherein means are provided for charging the energy store during a fraction of one time interval'in response to the signal and for keeping it charged during a predetermined period, and wherein a second energy store is provided which seeks to return the diverter after actuation.

By means of the constant unlocking operation during each cycle whereas the energy store is charged only when required, the paths of movement of the sheet articles can be changed within very short time intervals or the diverter can be kept inv one of its positions for a prolonged period, thereby making the diverter suitable for either of the aforementioned purposes. As long as the energy store remains charged, the diverter will remain in one of its positions and when it is discharged the diverter will remain in the other position. The use of a double-acting abutment on-the locking means ensures that, no matter in which position the diverter may be located, it is always freed for movement to the other position by pulling the abutment out of the path of the counter-abutment on the oscillatory lever. In this way, the diverter can always be released at the same instant within a time interval.

When one of the energy stores is to operate the diverter, it is desirable that it should not have to overcome an opposing force exerted by the other energy store because both energy stores can thereby be made smaller and consequently charged more rapidly. It is therefore preferred that the second energy store should also be chargeable. The two energy stores may be in the form of a single double-acting pneumatic pistoncylinder unit.

When using the actuating apparatus for diverting'isolated sheet articles, the control means are preferably such that they deliver a control signal during the passage of an article to be diverted and for the duration thereof. The charging means can comprise a cam rotatable in sequence with said equal time intervals and capable of delivering a sequence signal by momentarily actuating a switch, the charging means also comprising a comparator to which both signals are delivered and which, upon simultaneous arrival of both signals, is effective to generate a diverting signal causing charging of the energy store for actuation of the diverter. If both energy stores are chargeable, the comparator, upon arrival of a sequence signal but non-arrival of a control signal, can be effective to generate a different signal causing charging of the energy store for returning the diverter.

' Two examples of the invention will now be described with reference to the accompanying drawings wherein:

FIG. 1 is a diagrammatic side elevation of an actuating apparatus for a diverter located at a fork junction in the path of flat workpieces in the form of sheet articles, and

FIG. 2 is an electric block diagram for a modified actuating apparatus.

Referring to FIG. 1, sheet articles W (for example flattened tubular sections of plastics bag-making material) are moved at equal time intervals to a diverter 6 by means of sets of conveyor belts l and 2 that pass over guide rollers 3 and 4, respectively. The diverter 6 is located at a fork junction in the path of the articles W and is pivotable within limits about a shaft by means of actuating linkage comprising an actuating lever .7 on the shaft 5. Also connected to the shaft 5, and thus to the diverter 6, there is an oscillatory lever 8 carrying an abutment 8'. The articles W normally travel along the top face 9 of the diverter by being pushed or pulled thereover. Downstream of the diverter, the articles are fed by further sets of conveyor belts l2 and 13 passing over rollers and II, respectively. Between the belt rollers and the diverter, the articles are supported by guide rods I5 and 16 which pass, in the manner of the prongs of a comb, between the rollers 3, 4 and 10, 11, respectively.

A diverter path for the articles is defined by the underface 14 of the diverter 6 and a guide plate 17 downstream of the diverter, as well as by a set of conveyor belts 20 which are supported by guide rollers 18 and 19.

The actuating mechanism for the diverter 6 also comprises a shaft 2l,carrying a cam disc 22. The shaft 21 is rotated in sequence with the time interval between successive articles W fed by the belts I, 2, i.e., the shaft 21 executes one turn per pitch of the articles W. One arm 24 of a two-armed lever pivoted at 23 carries a cam follower roller 25 which is kept in contact with the disc 22 by a spring 46. The other arm 26 of the twoarmed lever has an abutment plate 27 of predetermined thickness bolted to it. Pivoted to the end of the actuating lever 7 opposite the shaft 5 there is a double-acting pneumatic piston-cylinder unit 28 comprising a cylinder 32, double-acting piston 29, piston rod 30, and hinge 31. The cylinder space or pressure chamber on each side of the piston 29 constitutes a separate energy store. The pressure chamber at the right-hand side of the piston 29 is charged with compressed air through the connection 33 when it is desired to bias the diverter 6 to swing upwardly from the position shown in full lines to that shown in broken lines, whereas the pressure chamber 36 is charged through the connection 34 when it is desired to bias the diverter 6 in the opposite direction.

Also mounted on the shaft 21 there is a further cam disc 37, the raised cam surface 37' of which cooperates with a microswitch 38 which delivers one short sequence signal during each cycle to a comparator 40. A control device 39 (which is disposed upstream of the diverter 6 in the path of the articles W but has, for clarity, been illustrated separately in the diagrammatic representation of FIG. 1) serves to scan successive articles W for irregularities. The control device 39 may be a photoelectric scanner which senses any misalignment in the articles W. As soon as a defect has been determined, the control device 39 delivers a control signal to the comparator 40. This control signal is ered to the comparator 40 simultaneously, the latter delivers a different signal, which may be termedadiarticles W are diverted into the path below the underface 14 of the diverter. The connectors 33 and 34 of the unit 28 are selectively applied to a pressure vessel 42 or to atmosphere by means of an electromagnetically actuable two-way valve 41. The pressure vessel 42 is constantly kept supplied with compressed air by a pump 43 operated by a motor 44.

The actuating apparatus for the diverter functions as follows. Provided that no defective articles pass through the control device 39, the latter will not generate a signal and consequently the comparator 40 delivers a free passage signal which simply results in the electromagnet of the valve 41 remaining de-energised, whereby the valve remains in its illustrated inoperative position under the action of a return spring. The lefthand pressure chamber 36 of the unit 28 is charged and the diverter 6 remains in the position shown in full lines in FIG. 1. In this position of the diverter, the abutment plate 8' on the lever 8 is held in such a position by means of an adjustable abutment 45 that the confronting faces of the abutment plates 8' and 27 are slightly spaced from one another. Accordingly, when the twoarmed lever 24, 26 is rotated as the cam follower roller 25 rides over the raised cam portion 22' of the cam disc 22, the plate 27 can be freely withdrawn past the plate 8 and subsequently returned to confront the plate 8 under the action of the spring 46. If the control device 39 has scanned a defective article and produced a prolonged control signal then, as soon as a sequence signal arrives at the comparator 40 from the microswitch 38, the comparator delivers a diversion signal to bring the valve 41 into its operative position. This .causes the pressure chamber 35 of the unit 28 to be connected'to the pressure vessel 42 and the pressure chamber 36 to be vented to atmosphere. The unit 28 therefore now biases the actuating lever 7 to swing the diverter 6 upwardly but such swinging movement cannot yet be executed because the abutment plates 8 and 27 lies against one another under pressure. At the instant that' the cam follower roller 25 rides on the raised cam portion 22', the two-armed lever 24, 26 is pivoted to withdraw the plate 27 from engagement with the plate 8', and this occurs at a very particular angular position of the rotating shaft 21, namely when the illustrated radius 47 of the cam disc 22 extends through the position of contact. between the cam follower roller 25 and raised cam portion 22.

As soon as the plate 8' has been released by the abutment plate 27, the previously charged energy store 35 is effective to swing the diverter 6 to the position shown in chain-dotted lines and the defective article W that was sensed by the control device 39 is diverted out of the normal path. The drive for the shaft 21 is set so that the coincidence of the radius 47 with the cam follower roller 25 occurs when the leading edge of an article W is at a predetermined distance from the tip 48 of the diverter 6. Since the passage of the articles W through the apparatus is determined by their leading edges, irrespective of their length, setting of the cam disc 22 in the manner just described in relation to the shaft 21 will ensure that the instant at which the diverter 6 is unlocked will always occur at the same time within each cycle.

An adjustable stationary abutment 50 enables the diverter 6, and thus the locking lever 8, to be held inan angular position at which the now confronting faces of the abutment plates 8' and 27 are slightly spaced apart to enable the plate 27 to be passed to and fro in front of the plate 8. If several defective articles happen to be scanned by the device 39 in succession, a control signal will be delivered each time and then a diversion signal will, be deliveredby the comparator 40 whenever the respective sequence signals arrive from the microswitch 38, the diverter 6"in this case remaining in'the raised or diverted position shown in chain-dotted lines. If the next article to arrive at the control device 39 is without defect, the control signal will disappear and, on arrival of the next sequence signal at the comparator 40, the latter will deliver a free, passage signal to charge the-pressure chamber or energy store 36 and prepare the actuating linkage for lowering of the diverter. However, displacement of the piston 29 and lowering of the diverter is not yet possible by reason of the locking effect of the abutment 27 It is only when the radius 47 coincides with the cam follower roller 25 that the abutment plate 27 will be withdrawn by swinging of the twoarmed lever 24, 26. At'this instant the trailing edge of the last article that had been diverted will already have passed the tip 48 of the diverter and the leading edge of the next following a rticle will not have yet reached the tip 48. Actuation of the diverter to the diverted position as well as its return to the normal position will always occur when the radius 47 coincides with the cam follower roller 25, i.e., always at'the same instant within each time interval at which the articles W are being fed. ln relation to the cam disc 22,'the cam disc 37 is set so that its raised cam portion 37' will actuate the microswitch 38 in good time before the radius 47 reaches the cam follower roller 25. Actuation of the microswitch 38 determines the time at which the respective energy store 35 or 36 is charged with compressed air. The time of charging of the energy store therefore precedes unlocking of the diverter by a period which is adequate to enable the energy store to be properly charged.

The actuating apparatus is suitable not only for sorting out defective sheet articles but also for sorting out flat accessories that are being continuously fed for subsequent co-operation with the main sheet articles. For example, in the manufacture of valved bags, the main sheet articles W would be flattened tubular sections of bag-making material and the accessories could be cover sheets for the valved cross-bottom closures of the bags. When a valved bag section has been diverted because it is defective or misaligned, then of course the associated 'cover sheet for the diverted bag section should not be provided with adhesive and applied in the space where the diverted bag section would normally have occurred. Instead, the appropriate cover sheet should also be diverted before it reaches an adhesive applicator. For this purpose, the control device 39 of FIG. 1 would not lie in the path of the cover sheets but in the path of the valved bag sections, the purpose of the device 39 being to, determine whether or not a bag section has arrived. If there is no bag section present, the device 39 will deliver a control signal.

A suitable block circuit diagram for such an installation is shown in FIG. 2. The sheet articles in the form of valved bag sections are indicated at S and they are being fed along a path 60. Disposed in this path there is a sensing switch 61 which serves as a control device.

Whenever a' bag section passes over the switch 61, a

contact is closed and no signal will be delivered but if the switch remains open because one of the bag sections is missing then it will fail to close the contact during this time and a control signal will be delivered. The

control switch is provided in the current supply for an actuating magnet of a relay. Connected in parallel to this current supply there is a switch 38 which cooperates with the cam disc 37 so that it is opened by the raised cam portion 37'. In series with this switch there is a switch 62 actuatable by a relay 64. The switch 62 is closed when the relay is energised and open when it v 61 and a sequence signal from the switch 38. As longas the control switch 61 remains closed by a bag section S passing thereover, the sequence switch 38 in parallel therewith may be temporarily opened. The relay 64 will nevertheless remain energised and the valve 41' will remain in its operative position at which the energy store 36 is charged to press the diverter into its normal lowered condition. If one of the bag sections S is missing, the control switch fails to close during this time. Prolonged opening of the sequence switch 38' will then cause the relay to become de-energised and open the switch 62, which remains open when the switch 38' is subsequently closed. The actuating magnet for the valve 41 thereby becomes de-energised and returns to the rest position as determined by its return spring, at which the energy store 35 becomes charged. In other respects, the actuating apparatus of FIG. 2 will function i in the manner described with reference to FIG. 1. The

control with electric current and electric switches can of course be readily replaced by analogous pneumatic control elements.

The actuating apparatusaccording to the invention is readily convertible for applications where a certain number of sheet articles are to be fed in one path, followed by a predetermined numberof articles in a different path, and so on. In this case the control means 39 or 61 would be replaced by a counter which delivers a control signal whilst a predetermined number of articles are being fed along one path and no signal at all whilst the next batch of articles is being fed along the second path.

I claim: Y

1. An actuating apparatus for a diverter for sheet articles moving at equal time intervals along a first path comprising a diverter positioned at a fork junction and being moveable between a first position where said articles are moved along said first path and a second position where selected articles are diverted out of said first path into a second path, an actuating linkage for causing said diverter to move to said second position in response to a signal, control means upstream of said fork junction for monitoring said articles moving along said first path and for delivering said signal, first energy storage means for biasing said actuating linkage so that said diverter is moved to said second position when energy is stored therein, means for storing energy in said first energy storage means during a fraction of one of said equal time intervals in response to said signal and for keeping energy stored in said first energy storage means for a predetermined period, second energy storage means for moving said actuating linkage so that said diverter is moved to said first position when energy is stored therein, locking means for holding said actuating linkage against the bias of said first energy storage means, a shaft rotatable in sequence with said equal time intervals, said locking means being coupled to said shaft and being releasable at least once during each of said equal time intervals, and a lever attached to said diverter, said locking means comprising a doubleacting abutment moveable into the path of said lever, said lever being moveable when said diverter is actuated and having corresponding abutments surfaces, said double-acting abutment being movable to lock said diverter in either said first or second positions.

2. The apparatus of claim 1 and a further comprising means for storing energy in said second energy storage means after actuation of said actuating linkage.

3. The apparatus of claim 2 in which said first and second energy storage means each comprise one chamber of a double-acting pneumatic piston cylinder unit.

4. The apparatus of claim 1 in which said control means issues a control signal during the passage of an article to be diverted and for a duration corresponding to said passage, wherein the means for storing energy in said first energy storage means comprises a cam rotatable in sequence with said equal time intervals, a switch activated by said cam to deliver a sequence signal, comparator means for comparing said control signal and said sequence signal and for generating a diverting signal when said sequence and control signals are simultaneously received to cause energy to be stored in said first energy storage means for actuating said diverter.

5. The apparatus of claim 1 in which said comparator means generates a signal to activate said means for storing energy in said second energy storage means for moving said diverter to said first position when said sequence signal but not said control signal is received at the input of said comparator means. 

1. An actuating apparatus for a diverter for sheet articles moving at equal time intervals along a first path comprising a diverter positioned at a fork junction and being moveable between a first position where said articles are moved along said first path and a second position where selected articles are diverted out of said first path into a second path, an actuating linkage for causing said diverter to move to said second position in response to a signal, control means upstream of said fork junction for monitoring said articles moving along said first path and for delivering said signal, first energy storage means for biasing said actuating linkage so that said diverter is moved to said second position when energy is stored therein, means for storing energy in said first energy storage means during a fraction of one of said equal time intervals in response to said signal and for keeping energy stored in said first energy storage means for a predetermined period, second energy storage means for moving said actuating linkage so that said diverter is moved to said first position when energy is stored therein, locking means for holding said actuating linkage against the bias of said first energy storage means, a shaft rotatable in sequence with said equal time intervals, said locking means being coupled to said shaft and being releasable at least once during each of said equal time intervals, and a lever attached to said diverter, said locking means comprising a double-acting abutment moveable into the path of said lever, said lever being moveable when said diverter is actuated and having corresponding abutments surfaces, said double-acting abutment being moveable to lock said diverter in either said first or second positions.
 2. The apparatus of claim 1 and a further comprising means for storing energy in said second energy storage means after actuation of said actuating linkage.
 3. The apparatus of claim 2 in which said first and second energy storage means each comprise one chamber of a double-acting pneumatic piston cylinder unit.
 4. The apparatus of claim 1 in which said control means issues a control signal during the passage of an article to be diverted and for a duration corresponding to said passage, wherein the means for storing energy in said first energy storage means comprises a cam rotatable in sequence with said equal time intervals, a switch activated by said cam to deliver a sequence signal, comparator means for comparing said control signal and said sequence signal and for generating a diverting signal when said sequence and control signals are simultaneously received to cause energy to be stored in said first energy storage means for actuating said diverter.
 5. The apparatus of claim 1 in which said comparator means generates a signal to activate said means for storing energy in said second energy storage means for moving said diverter to said first position when said sequence signal but not said control signal is received at the input of said comparator means. 